The present invention relates generally to a surgical table and more particularly to a surgical table suited for surgery performed under x-ray.
Recent developments in medical and surgical procedures have created a need for specialized surgical tables which position a patient in a predetermined posture. To this end a number of specialized tables and other devices have been developed, particularly in the fields of obstetrics and gynecology. For example, U.S. Pat. No. 3,817,512 (Torrey) discloses a device which may be used as a portable examination table to examine the pelvic or rectal area of a patient. The device disclosed by Torrey includes a table which is pivotally supported on a base and a pair of leg supports disposed on opposite sides of the table. During examination, the table is placed under the patient's buttocks and the patient's legs are placed in the adjustable leg supports. The table and leg supports are adjusted such that the patient assumes a position which properly exposes the area which is to be treated.
U.S. Pat. No. 3,318,596 (Herzog) discloses a surgical table particularly suited for use in obstetrics. The surgical table includes adjustable leg rests articulated to a table which includes an adjustable backrest. The adjustment of the leg rests and the backrest may be synchronized to place the patient in a desired position for the physician.
Other devices which may be used to position a patient during obstetric procedures are taught in: U.S. Pat. No. 4,557,260 (Reyes, Jr.) which discloses a hip lifter or pelvic support for supporting and positioning the pelvic portion of a patient in an elevated position during examination; U.S. Pat. No. 4,221,370 (Redwine) which discloses an obstetric chair which adjusts in elevation and attitude, and includes channel-like thigh supports to position the patient's legs; and U.S. Pat. No. 4,225,127 (Strutton) which discloses a device for positioning an expectant woman during child birth. The Stratton device includes a table (which forms a chair seat), a pivotally mounted chair back, and a pair of leg supports pivotally mounted from the table. This arrangement allows the position of the expectant woman to be changed from a supine position to a squatting position during delivery.
Other devices are also available for positioning patients during post surgery treatment. For example, U.S. Pat. No. 3,759,252 (Berman) discloses an apparatus for hip dislocation treatment. The apparatus includes means for securing and immobilizing the leg and hip bones of a patient in a selected position during the healing period of the hip dislocation.
Although the devices disclosed above are useful for gynecological, obstetric and post surgical healing procedures, they are not particularly well suited for surgery of the lower limbs of a patient.
Although some efforts have been devoted to developing orthopedic operating tables for lower limb surgery, a surgical table which provides a comfortable arrangement for the patient has not been developed. Existing tables such as the "Orthopedic System Orthomicron," which is commercially available from Marzet Aubry of Paris, France, are designed for lower limb surgery work performed under x-ray control devices such as C-arm image intensifiers. The Marzet Aubry table includes a traction arm which may be articulated in any direction, a pelvic support which adjusts horizontally to accommodate the use of x-ray machines such as the C-arm, and a table top which supports the upper body of a patient. The traction unit is adjustable in abduction, adduction and also in tilting to accommodate surgery on a flexed leg. The table provides unobstructed access to the pelvic area of a patient. Although this design accommodates surgical procedures which require the use of C-arm x-ray machines, the design and construction of this table are not ideally suited for the comfort of the patient. Further, the Marzet Aubry table is not operative to adequately secure a patient in the atavistic position (discussed below) which is desirable in certain surgical procedures.
As stated above, the design and construction of existing lower limb surgical tables may provide a source of discomfort for patients. First, the construction of existing tables makes it difficult for a patient with a lower limb injury to climb onto the table. Second, the table typically includes a post which is disposed in the perineum (crotch area) of the patient for securing the patient on the table. This post provides a source of discomfort, particularly when the patient's legs are in traction.
For surgical procedures such as the method of installing an endoprosthesis in the hip taught in U.S. Pat. No. 4,714,478 (Fischer), it is particularly desirable for the thigh of the patient to be in an atavistic position. An atavistic position is defined as the position of the thigh such that the femoral head is completely within the acetabulum. A patient's femoral head is normally one-third outside of the acetabulum when the patient is in a supine position. Typically, the atavistic position is assumed at 80.degree. flexion and 10.degree. abduction.
In the method taught by Fischer, a portal is drilled through the lateral cortex of the femur at a location opposite the ball of the femur. The ball of the femur is then removed by drilling through the femoral neck into the femoral head. The endoprosthesis is then inserted through the portal. The procedure is facilitated if the femoral head is completely within the acetabulum. It is also desirable for a surgical table used in such a procedure to provide unobstructed lateral access to the pelvic area as well as an unobstructed x-ray path through the hip joint.
Although existing surgical tables may be adjusted to position the leg of a patient, they do not provide adequate measures for positioning the leg of a patient such that the thigh assumes the anatomical thigh position (the atavistic position). Further, existing surgical tables such as the Marzet Aubry device, when used to position the patient's leg in a flexed position, do not fully secure the leg to a point where the surgical procedure taught by Fischer may be performed.
Therefore, in view of the above, it is an object of the present invention to provide a comfortable surgical table which provides unobstructed lateral access to the pelvic area of a patient.
It is a further object of the present invention to provide a surgical table which may be used to position and secure the thigh of a patient in a predetermined degree of abduction and flexion.
It is still a further object of the present invention to provide a surgical table which may be used for x-ray controlled surgical procedures in the pelvic area.